Types and genetic model of Precambrian granitoids of South China

Precambrian granitoids in South China, including more than 20 bodies, are distributed on the Jiangnan ancient continent covering Guangxi, Jiangxi, Anhui and Zhejiang Provinces. The total area of granitoids is about 4300 km³, less than 2.5% of whole area of the Jiangnan ancient continent. According to the features of the representative bodies the Precambrian granitoids in South China may be divided into four genetic types: (1) mantle-derived granitoids crystallized from differentiated basic magma; (2) cordierite-bearing magmatic granitoids whose source rocks are mainly oceanic igneous rocks; (3) cordierite-bearing magmatic granitoids originated mainly from pelitic metamorphosed basement; (4) metasomatic granitoids caused by metasomatism of metamorphosed pelitic rocks. Except for the first type, the other three types essentially belong to the S-type granite in the current classification of granites. Tectonically, they are of collision granitoids irrelevant to subduction.